Investigators traced the fire aboard a UPS plane, which crashed in Dubai on Sept. 3, 2010, to lithium batteries in the cargo. Fire and smoke overwhelmed the two pilots, who died in the crash. / AP

by Bart Jansen, USA TODAY

by Bart Jansen, USA TODAY

Crash investigators in the United Arab Emirates traced the fire that destroyed a UPS plane in 2010 to the cargo of lithium batteries, and found that smoke-detection equipment took too long to alert the crew, according to a report released Wednesday.

That country's General Civil Aviation Authority found that heat from the fire disabled the crew's oxygen system and that toxic smoke filled the cockpit within three minutes of the first alarm, obscuring the view of controls and terrain.

Both crewmembers were killed when the 747-44AF crashed Sept. 3, 2010, near Dubai.

The authority recommended in its 322-page report that the Federal Aviation Administration and its European counterpart develop better firefighting standards and equipment for cargo planes, with visual warnings about where a fire is located.

The crash highlighted the risks of lithium batteries, which are being investigated in more recent incidents. The U.S. National Transportation Safety Board held a two-day meeting in April to learn more about the batteries that are embraced for being smaller and recharging faster than other batteries, but that carry the risk of overheating.

Batteries that power the 787 Dreamliner â?? and overheated aboard two planes -- prompted the FAA to ground the planes for months earlier this year while Boeing developed better insulation within the batteries and a metal shell to contain any potential fire.

And British investigators traced a fire this month aboard a Dreamliner at Heathrow airport to an emergency transmitter powered by a lithium battery, although it was unclear whether the battery or a short-circuit outside it sparked the fire.

Lithium batteries are allowed on cargo planes, but they face some restrictions in the cargo of passenger planes. Federal regulations limit lithium-metal batteries, which are typically in watches and cameras, in the cargo of passenger planes to 11 pounds per package, so long as kept in equipment such as a camera. But regulations allow unlimited packages of lithium-ion batteries, the rechargeable kind typically found in laptops and cell phones, so long as they are carefully packed.

UPS said it has already developed fire-containment covers for cargo, adopted full-face oxygen masks that are easy to put on and enhanced emergency training. The company said it has ordered 1,821 fiber-reinforced plastic shipping containers to withstand intense fires f

or up to four hours, giving pilots more time to land.

"UPS has a long history as an aviation safety leader," spokesman Malcolm Berkley said in a statement.

The president of the Independent Pilots Association, the union representing UPS pilots, encouraged the FAA and UPS to quickly implement technology for suppressing and containing fires.

"We tragically lost two of our best pilots in the Dubai crash," said Robert Travis, the union president. "As UPS pilots, we are determined to do everything in our power to minimize the risk associated with on-board smoke and fire events."

The crew in Dubai reported a fire about 22 minutes into the flight and tried to return to the airport to land. But smoke obscured the pilot's view of flight-control instruments and radios. The captain's oxygen supply stopped working five minutes after the initial fire warning, at about 21,000 feet in the air, leaving him incapacitated for the rest of the flight.

"I got no oxygen I can't breathe," the captain said, according to a transcript of the cockpit-voice recorder. "You fly."

With the first officer unable to see outside the cockpit or the controls within it, the plane flew past the airport and crashed while trying to circle the airport.